We report the observation of a small but finite valley Hall effect (VHE) signal in two-dimensional MoS2 channels which is grown on SiO2/Si substrates under the circularly polarized light. And the angular dependence of VHE in two-dimensional MoS2 is studied. The VHE signal is a periodic function (period pi) but with a phase shift, which confirms the presence of strong coupling between spin and valley. Furthermore, using a weak measurement under the condition of the optical circular dichroism, we find resembling beating phenomena, which suggests that a static electric field can induce oscillations. It is interesting that the interval time of the peak starts from an certain value, which is related to carrier densities. We suppose that this certain value is explained by a quasi-two-dimensional electron gas model, which is based on the Hall conductance quantized value of e(2)/h. To our knowledge, it is the first experiment that realizes such quantized values. (C) 2016 Elsevier B.V. All rights reserved.